Several techniques exist for the mounting of a solar panel on a structure. According to a first mounting technique, the solar panel can be positioned on top of the structure or slid along the structure. It is then secured to the structure with clips or connectors or it is secured to the structure with screws and bolts. A second mounting technique relies on sliding one or more solar panels along a profile designed to ensure the solar panel is secured to the structure with a reduced need for clips or connectors or other mounting means.
US 2006/0086382 is an example of the first mounting technique. The document discloses an assembly for mounting solar modules on a structure. The assembly comprises an upper rail, which is continuous and acts as a top cover for the solar, and a lower rail, which is the panel support on which the solar panel rests. The two rails are continuous along the length of the solar panel, and are secured together using a screw and a bolt. The upper rail and the lower rail are structured relative to each other so that at least one of them is moveable relative to the other one. The two rails secure the solar panel when the distance between the top cover and the panel support is equal to the thickness of the mounted solar panel.
The assembly disclosed in US 2006/0086382 relies on the use of two independent rails that are secured by means of bolts in order to be able to adapt to the thickness of different solar panels. The resulting torsion stiffness of the assembly, amongst other things, is dependent on the resistance of the screws and bolts. In order to enable the assembly to easily adapt to solar panels of different thickness, the upper and lower rail which are moveable relative to each other further do not demonstrate such a good bending strength and stiffness against vertical loads as it would have when the assembly would have been made in one piece, because of a reduced modulus of resistance and moment of inertia. The resistance of the resulting assembly to the weight of the mounted solar panel is important as such profiles need to have a considerable free span and so a good bending stiffness and resistance. Additionally, the screw and bolt 27 depicted on FIG. 6 prevent a solar panel from being secured closely to the two rails, and will avoid to easily slide the solar panel during mounting, as the channel in which the solar panel will be slid comprises lateral obstacles that will obstruct the sliding motion of the solar panel.
The screws and bolts that secure the profile disclosed in US 2006/0086382 need to be individually fastened, which drastically increases the mounting time. Furthermore, when several solar panels are positioned on the structure, the mounting is made more complex as solar panels located high above the ground need to be individually fastened to the structure. Such mounting structures, also known as solar tables can for example contain up to 6 solar panels oriented in landscape direction, which would for example result in a 6 meters-long mounting profile. These solar panels are mounted on the mounting profiles of the solar table inclined at an angle of for example 25 degrees. The highest point of such a solar table would then be located 3 meters above the ground, which is too high to reach from the ground by an operator installing the solar panels. The mounting of the solar panels on the solar table therefore would require extra equipment to access the high positioned solar panel, which increases the time and complexity of the mounting operation. The mounting of the solar panels at locations that cannot be reached from ground level could alternatively be executed by the technician by stepping on top of the already assembled solar panels to access the highest point. It is clear that this could result in damage of the already mounted solar panels and/or a reduction of their energy conversion efficiency.
The top cover and the panel support disclosed in US 2006/0086382 are continuous, which means they extend continuously along the longitudinal direction along the entire length of the panel support, thus partly covering the solar panel in a continuous way. The use of the material is not optimized, which increases the production costs, and which results in the manufacturing of a heavy structure. The weight of the assembly makes its mounting difficult and dangerous. Also, the friction induced by the large contact area of the continuous panel support with the solar panel during the sliding motion of the solar panel during its mounting is high. This makes the mounting difficult as extra force needs to be deployed to counteract the friction on the solar panel during sliding.
EP 2 413 381 discloses a continuous panel support on which a solar panel is slid (depicted in FIG. 12 as element 1140b). The frame of the solar panel itself needs to be designed to be able to slide along the rails of the profile. Solar panels are produced as commodity products, which makes them cheap. But the need for a special frame leads to additional costs which make the option disclosed in EP 2 413 381 expensive. Additionally, in order to reduce the friction induced by the continuous panel support and to facilitate the sliding movement of the solar panel, a low friction slidable surface such as Teflon-coated surface is applied on top of the panel support. This additional processing step however makes the manufacturing of the profile more complex.
EP 2 495 508 is another example of the first mounting technique. The document discloses a retaining clip for the assembly of solar panels on a profile. FIG. 17 shows an embodiment of such a retaining clip formed from a strip of material. The retaining clip comprises a top cover, a vertical wall, a panel support and two support pillars used to fixate the retaining clip to the profile. The clip is formed from a metal plate that is bent at right angles along its upper and lower edges, thereby respectively forming the top cover and the panel support and the vertical wall between the top cover and the panel support. The solar panel is positioned in the formed chamber between the top cover and the panel support, and rests on the panel support itself. The two bent-over strips forming the top cover and the panel support are divided into sections of the metal plate which are alternatively bent in opposite directions perpendicularly to the strip of material. Therefore, the top cover as well as the panel support are discontinuous along the direction of one dimension of the solar panel.
The top cover and the panel support of the retaining clip disclosed in EP 2 495 508 are formed of material of the vertical wall, by bending it at right angles respectively along its upper and lower edges. The solar panel rests on the panel support, positioned at the lower edge of the vertical wall. The flanges of the profile disclosed in EP 2 495 508 are not continuous. As a consequence, it presents a limited bending strength and stiffness around the strong axis.
The fact that the top cover disclosed in EP 2 495 508 is discontinuous also implies that the solar panel is more subject to damage at positions where it is not protected by the top cover. Indeed, under rainy and other difficult weather conditions, humidity as well as dirt, such as dust, leaves and branches, can accumulate at the edges of the top cover. On a long term basis, this will damage the solar panel and in any case reduces its conversion efficiency.
The top cover disclosed in EP 2 562 488 is not continuous. Under rainy and other difficult weather conditions, humidity as well as dirt, such as dust, leaves and branches, can accumulate at the edges of the top cover. Moreover, the discontinuities in the top cover form obstructions that prevent dirt from streaming downwards and will therefore be collected on top of the solar panel, which will reduce its performance. Also, when the profile is made out of a metal, in the outdoor environment it can react with a different metal, for instance the metal forming the frames of the solar panels, resulting in corrosion and degradation of the solar panel itself, especially when humidity and dirt can freely act as a catalyser for this process. On a long term basis, dirt and corrosion thus cause damage the solar panel which then reduces its energy conversion efficiency. Such long term effects are important as solar panels must however are expected to operate during a long-term period of for example 25 years from delivery and mounting.
EP 2 562 488 is an additional example of the second mounting technique. The document discloses a profile for holding a photovoltaic or solar collector module. The profile is formed by bending a single sheet metal plate and comprises a bottom support (depicted in FIG. 2 as element 7), a vertical wall (depicted in FIG. 2 as element 5), a panel support (depicted in FIG. 2 as element 10) and a top cover (depicted in FIG. 2 as element 4). The solar panel is positioned in the chamber created between the top cover and the panel support. The panel support presents a U-shaped form in cross-section. The top cover is intermittently formed along the length of the vertical wall. The panel support is continuously formed along the entire length of the vertical wall. The U-shape is formed by bending the sheet metal plate.
The chamber from EP 2 562 488 in which the solar panel is positioned is obtained by rolling and bending a single sheet metal layer. Therefore, the manufacturing process is adapted so that a fixed distance between the top cover and the panel support is delivered. This means that the manufactured profile is only compatible with a pre-determined thickness of solar panel. As soon as the thickness of the solar panels to be mounted on the profile changes, each manufacturing step defining and following the definition of the top cover and the panel support needs to be adapted to take the corrected distance between the top cover and the panel support into account. This is a complex and time-consuming process, which requires adjustments and reconfigurations of the parameters of the production line.
The strength and the resistance to torsion of the profile disclosed in EP 2 562 488 are limited. There is a high risk that such a profile will bend under the weight of the mounted solar panel or will deform during the mounting of the solar panel. This leads to additional time dedicated to the mounting of the solar panel.
DE202012008175 discloses an insertion profile for photovoltaic elements and an associated mounting system wherein the insertion profile demonstrates a special geometry using punched through tabs allowing further insertion of a photovoltaic module. FIG. 7 of DE202012008175 depicts an embodiment of such a structural profile that is similar to that schematically illustrated in FIG. 1A-B, FIG. 13 and FIG. 14. As visible in FIG. 1A and FIG. 1B, the structural profile 1 comprises a single wall 10, a panel support 13, an opening 14, a top cover 16 and a base section 17. The structural profile 1 is formed in a single metal plate, for instance aluminium or preferably steel. The height of the structural profile 1 and its wall 10 is defined along the height direction of the axis 5, and the width of the structural profile 1 is defined along the width direction of the axis 4. The top cover 16 extends from the single wall 10. This means that the top cover 16 projects from the plane of the wall 10. The base section 17 also extends from the wall 10, on the same side of the wall 10 as the corresponding top cover 16, and at a position below its corresponding top cover 16. Although, as shown in the embodiment of FIG. 1A and FIG. 1B, the top cover 16 and base section 17 project transverse from the vertical plane of the wall 10, it is clear that alternative embodiments are possible in which the angle at which the top cover 16 and or the base section 17 project from the plane of the wall 10 at another suitable angle. As shown, the panel support 13 also extends from the wall 10 on the same side of the wall 10 as the corresponding top cover 16. The panel support 13 is positioned below the corresponding top cover 16 and above the corresponding base section 17. As the panel support 13 is positioned between the top cover 16 and the base section 17, it is also clear that the distance from the panel support 13 to the top cover 16 is smaller than the height of the wall 10. The panel support 13 comprises a panel support section 12 formed of material taken from the wall 10. In general the panel support 13 is positioned below its corresponding top cover 16 such that a solar panel 2 can be slid between the panel support 13 and its corresponding top cover 16 Both the top cover 16 and the base section 17 are substantially continuous along said length direction 3 of the wall 10. As shown in FIG. 7 of DE202012008175, the structural profile 1 thus comprises a plurality of panel support sections 12 formed of material taken from the wall 10 from which its corresponding top cover 16 extends, the panel support sections 12 being spaced along the length direction 3 and arranged at substantially the same height along the wall 10. The panel support 13 is therefore discontinuous along the length direction 3. The lateral view shown in FIG. 1B is periodically repeated along the length direction 3 of the wall 10 of the structural profile 1 as shown in FIG. 7 of DE202012008175. According to an alternative embodiment, the panel support 13 can be repeated following a periodic pattern along the length direction 3 of the wall 10 of the structural profile 1 such that the panel support 3 can alternate on each side of the wall 10 along the length direction 3, as schematically illustrated in FIG. 8 of DE202012008175 and as schematically illustrated in the lateral view on FIG. 14.
The fact that in DE202012008175 the material taken for forming the panel support sections 13 is taken close to the neutral axis reduces the resistance of the structural profile to bending in the plane parallel to the wall 10 which forms the web of the structural profile 1. In other words, the fact that the structural profile 1 comprises a single wall 10 from which material is taken to form the panel support 13 reduces the bending stiffness and the bending strength around the strong axis of the structural profile 1, as the moment of inertia is largely determined in function of the height of the web formed by the first wall 10 and the width of the flanges formed by the continuous top cover 16 and the continuous base section 17. The modularity of the assembly formed by the structural profile 1 and the solar panels 2, 6 is considerably reduced due to the fact that the structural profile comprises a single wall 10. Indeed, as depicted in FIG. 1 of DE202012008175, two different types of structural profiles are used in the assembly of the structural profiles and the solar panels. The structural profiles labelled 11 and 13 on FIG. 1 of DE202012008175 are structural profiles with a single wall with panel supports made of material taken from the single wall. In order to assemble the solar panels and the structural profiles of FIG. 1 of DE202012008175, the panel supports extend on the same side of the structural profile such that the solar panel can rest on the panel supports. The structural profile labelled 12 on FIG. 1 of DE202012008175 is a structural profile with a single wall with panel supports made of material taken from the single wall but extending on both sides of the structural profile such that solar panels can rest on panel supports on both sides of the structural profile. In other words, the structural profile labelled 12 on FIG. 1 of DE202012008175 comprises alternating panel supports such that solar panels can rest on panel supports on both sides of the single wall of the structural profile. The assembly of the structural profiles and of the solar panels therefore requires the manufacturing of two different types of structural profiles, which increases the complexity of the assembly and of the manufacturing, as well as the costs generated by the manufacturing and the time needed to assemble the structural profiles and the solar panels.
DE202012008175 describes an assembly for which solar panels are loaded on structural profiles in several consecutive steps. As depicted in FIG. 1 of DE202012008175, three structural profiles are mounted to form a frame on which solar panels are going to be assembled. Once the structural profiles are suitably mounted together, a solar panel is positioned such that the longest sides of the solar panel are parallel to the width direction 4 depicted in FIG. 13. The solar panel is then tilted under a suitable angle with respect to the width direction 4 of FIG. 13 such that the solar panel can be inserted between the top cover of a structural profile and a panel support of the corresponding structural profile, such that the solar panel rests on a panel support of the structural profile. The angle between the solar panel and the width direction 4 of FIG. 13 is then reduced until the solar panel rests on the panel support of another structural profile of the frame. For example, in FIG. 1 of DE202012008175, a first row of solar panels is for example tilted under a suitable angle with respect to the width direction 4 of FIG. 13 and the solar panels are inserted between the top cover of the structural profile 12 and the panel supports of the structural profile 12 that are formed of material taken from the single wall of the structural profile 12 and extend in the same direction as the width direction 4 of FIG. 13. As visible in FIG. 1 of DE202012008175, the angle between the solar panels and the width direction 4 is then reduced until the solar panels rest on the panel supports of the structural profile 12 of FIG. 1 of DE202012008175. Similarly, in FIG. 1 of DE202012008175, a second row of solar panels is for example tilted under a suitable angle with respect to the width direction 4 of FIG. 13 and the solar panels are inserted between the top cover of the structural profile 12 and the panel supports of the structural profile 12, formed from material taken from the single wall of the structural profile 12 but extending in the opposite direction of the width direction 4 of FIG. 13, i.e. in the opposite direction of the panel supports on which the first row of solar panels rests. As visible in FIG. 1 of DE202012008175, the angle between the solar panels and the width direction 4 is then reduced until the solar panels rest on the panel supports of the structural profile 12 of FIG. 1 of DE202012008175. There exists a risk that the solar panels are positioned at the furthest edge of the panel supports of the structural profiles from the single wall, as illustrated on FIG. 5 of DE202012008175 where the solar panel labelled 21 rests on the edge of the panel support labelled 15 the furthest from the single wall labelled 13. This increases the risk that solar panels slip from the panel supports and are damaged if the solar panels slip from between the top cover and the corresponding panel support and fall on the floor. For example, in FIG. 1 of DE202012008175, after a solar panel is inserted under a suitable angle between the top cover and the corresponding panel support of the structural profile labelled 11 on FIG. 1 of DE202012008175, the angle between a solar panel of the first row and the width direction 4 may be reduced until the solar panel rests very close to the edge of the free end of a corresponding panel support of the structural profile labelled 12 on FIG. 1 of DE202012008175. There exists a risk that this solar panel will not be securely resting between the top cover of the structural profile labelled 12 on FIG. 1 of DE202012008175 and the corresponding panel support and there exists a risk that the solar panel slips and drops from the structural profile labelled 12 on FIG. 1 of DE202012008175. The solar panel may then also slip from in between the top cover and a corresponding panel support of the structural profile labelled 11 on FIG. 1 of DE202012008175 and may as a result fall on the ground and be consequently damaged. Alternatively, there exists a risk that the solar panel does not entirely slip from in between the top cover and a corresponding panel support of the structural profile labelled 11 on FIG. 1 of DE202012008175, but is then submitted to a torsion as one edge of the solar panel is secured on a structural profile and the opposite edge of the solar panel hangs free. This can result in cracks in the structure of the solar panel. These possible damages considerably jeopardize the intrinsic quality of the material of the solar panels and therefore reduce the overall conversion efficiency of the solar cells of the solar panel. Additionally, the fact that during the mounting operation the solar panels must be positioned at the furthest edge of the panel supports of the structural profiles, furthest away from the single wall, such as illustrated in FIG. 5 of DE202012008175 results in large torsional forces acting on the panel supports hinging from the single wall of the structural profile. Indeed, on FIG. 5 of DE202012008175, the weight of the solar panel labelled 21 is not spread over the surface of the panel support parallel to the width direction 4, but the weight of the solar panel labelled 21 mainly leans on the edge of the panel support labelled 15 the furthest from the single wall labelled 13. This drastically increases the stress induced on the panel support, and on the single wall of the structural profile. There exists a risk that either the panel support bends under the weight and the pressure induced by the solar panel at the junction between the panel support and the single wall, and/or that the single wall itself bends under the weight and the pressure induced by the solar panel. As the top cover of the structural profile is continuous, a bent of the single wall threatens the integrity of the entire assembly of solar panels already assembled to the same structural profile. This may result in damage of solar panels already assembled to the same structural profile that may fall on the ground. Additionally, as the top cover of the structural profiles labelled 11, 12 and 13 in FIG. 1 of DE202012008175 is continuous along the length direction 3 depicted in FIG. 14, a limitation associated to the assembly depicted in FIG. 1 of DE202012008175 is that all the solar panels of the first row or of the second row must be simultaneously assembled with the structural profiles in order to guarantee that all the solar panels of the same row securely rest on the panel supports of the structural profiles as described above. It is only then that the structural profiles labelled 11,13 can be moved by elements 51,52,53 closer to structural profile 12 along a direction transverse to their length direction for securely inserting the opposing edges of the solar panels between their continuous top cover and the panel supports. This limits the modularity: the assembly must comprise structural profiles labelled 11, 13 at the top and the bottom of the assembly that are movable in order to secure the solar panels. Only two rows of solar panels can then be securely mounted: one row between the structural profile labelled 11 and the structural profile 12 and one row between the structural profile labelled 13 and the structural profile 12. This further reduces the ergonomics of the mounting operation for the assembly of structural profiles and solar panels. Indeed, the highest row of the assembly is difficult to reach as the assembly lies under an angle with respect to a horizontal direction. This increases the complexity of the mounting of solar panels on the highest row of the assembly. Also, the highest row comprises solar panels that must secured between the structural profile labelled 11 and the structural profile 12 one by one by the previously described tilting operation. This further increases the complexity of the mounting of solar panels on the highest row of the assembly. Additionally, mounting solar panels on the assembly of DE202012008175 requires that the structural profiles labelled 11,13 are beforehand carefully positioned with respect to the structural profile 12 in order to allow the insertion of solar panels in between their respective top covers and their respective corresponding panel support, without having the solar panels falling of their panel supports. This further increases the complexity of assembling the solar panels and the structural profiles. Additionally, the assembly described in DE202012008175 requires to coordinate the movement of all the elements 51,52,53 of a structural profile when all the solar panels of one row are mounted such that all the solar panels on this row are simultaneously and correctly secured by the respective structural profiles labelled 11,13 in a final mounted position.
WO2010/054617 describes an assembly for which solar panels are loaded on structural profiles in several consecutive steps. As depicted in FIGS. 9 to 11 of WO2010/054617, a solar panel labelled 2 is first inserted under an angle between the top cover and the corresponding panel support of a structural profile labelled 7a, as depicted in FIG. 9 of WO2010/054617. The angle between the solar panel labelled 2 and the frame structure labelled 5 is then subsequently decreased until the solar panel labelled 2 touches a structural profile labelled 7b, non-identical to the structural profile labelled 7a as it does not comprise a top cover, positioned parallel to the structural profile labelled 7a. The solar panel labelled 2 then rests on the panel supports of the structural profiles labelled 7a and 7b in a final mounted position, as depicted in FIG. 10. The solar panel labelled 2 is then securely fixed to the frame structure labelled 5 when a mounting operator manually inserts the element labelled 23 in the structural profile labelled 7b, thereby securely clamping the solar panel labelled 2 to the structural profile labelled 7b, between the element 23 and the panel support of the structural profile labelled 7b, as depicted in FIG. 11. The limitations of the assembly from WO2010/054617 are similar to the limitations of the assembly from DE202012008175 and previously described. The solar panels in WO2010/054617 are tilted to be inserted in the structural profiles of the assembly, which increases the complexity of the mounting of solar panels on the frame structure labelled 5. The ergonomics for mounting such an assembly are limited, especially with respect to the higher row of solar panels which is difficult to reach and for which an operator not only has to position solar panels in the structural profiles labelled 7a, but also has to securely clamp the solar panels to the frame structure labelled 5 by manually clicking the element labelled 23 from the top side after the solar panels are have been positioned on the assembly. Additionally, the assembly described in WO2010/054617 requires the use of a combination of two different structural profiles, labelled 7a and 7b in FIGS. 9 to 11 of WO2010/054617. Indeed, a solar panel can only be secured on the frame structure labelled 5 when it is secured between a structural profile labelled 7a and a structural profile labelled 7b. This reduces the flexibility and increases complexity of the assembly described in WO2010/054617, and the associated mounting operation. Additionally as profile labelled 7b comprises only discrete clamping elements, there is a high risk of moisture and dirt accumulating, and a consequent risk for corrosion and decrease of efficiency of the solar panels. Additionally as the continuous top covers of the profiles labelled 7a are substantially horizontal along their length direction, they form a continuous barrier for any moisture, dirt, etc. flowing along the solar panels under influence of gravity, thereby also increasing the consequent risk for corrosion and decrease of efficiency of the solar panels.
It is an objective of the present invention to disclose a profile and the related manufacturing process that overcome the above identified shortcomings of existing profiles. More particularly, it is an objective to disclose a profile that is easily adaptable to the different thicknesses of solar panels. It is a further objective to disclose a profile that is easy to fabricate, lightweight, mechanically strong, and reduces the manufacturing and installation cost as well as the waste of material. It is a further objective to disclose a profile that enables to deploy solar installations with increased lifetime, reduced maintenance costs and increased conversion efficiency.